The upper tracing is EEG, and the lower is a 10 Hz timing signal. Swartz in Electroencephalography and Clinical Neurophysiology. InPolish physiologist Adolf Beck published an investigation of spontaneous electrical activity of the brain of rabbits and dogs that included rhythmic oscillations altered by light.
During the procedure, electrodes consisting of small metal discs with thin wires are pasted onto your scalp.
The electrodes detect tiny electrical charges that result from the activity of your brain cells. The charges are amplified and appear as a graph on a computer screen, or as a recording that may be printed out on paper. Your healthcare provider then interprets the reading. He or she pays special attention to the basic waveform, but also examines brief bursts of energy and responses to stimuli, such as flashing lights.
Evoked potential studies are related procedures that also may be done. These studies measure electrical activity in your brain in response to stimulation of sight, sound, or touch. Why might I need an EEG? The EEG is used to evaluate several types of brain disorders.
When epilepsy is present, seizure activity will appear as rapid spiking waves on the EEG. The EEG may also be used to determine the overall electrical activity of the brain for example, to evaluate trauma, drug intoxication, or extent of brain damage in comatose patients.
The EEG may also be used to monitor blood flow in the brain during surgical procedures. There may be other reasons for your healthcare provider to recommend an EEG.
What are the risks of an EEG? The EEG has been used for many years and is considered a safe procedure. The test causes no discomfort.
The electrodes record activity. They do not produce any sensation. In rare instances, an EEG can cause seizures in a person with a seizure disorder. This is due to the flashing lights or the deep breathing that may be involved during the test.
Other risks may be present, depending on your specific medical condition. Certain factors or conditions may interfere with the reading of an EEG test. Low blood sugar hypoglycemia caused by fasting Body or eye movement during the tests but this will rarely, if ever, significantly interfere with the interpretation of the test Lights, especially bright or flashing ones Certain medicines, such as sedatives Drinks containing caffeine, such as coffee, cola, and tea while these drinks can occasionally alter the EEG results, this almost never interferes significantly with the interpretation of the test Oily hair or the presence of hair spray How do I get ready for an EEG?
Ask your healthcare provider to tell you what you should do before your test. Below is a list of common steps that you may be asked to do. Your healthcare provider will explain the procedure to you and you can ask questions.
You will be asked to sign a consent form that gives your permission to do the procedure. Read the form carefully and ask questions if something is not clear. Wash your hair with shampoo, but do not use a conditioner the night before the test. Do not use any hair care products, such as hairspray or gels.
Do not stop using medicines without first consulting your healthcare provider.
Some EEG tests require that you sleep through the procedure, and some do not. Avoid fasting the night before or the day of the procedure. Low blood sugar may influence the results.
What happens during an EEG? An EEG may be done on an outpatient basis, or as part of your stay in a hospital. Talk with your healthcare provider about what you will experience during your test.Electroencephalogram (EEG) Back to Neurological Tests and Procedures.
but do not use a conditioner the night before the test. Do not use any hair care products, such as hairspray or gels. you may also be admitted to the hospital for prolonged EEG (hour EEG) monitoring.
In cases where prolonged inpatient monitoring is not possible. neurological outcome (Cerebral Performance Category score 1–2). cephalogram monitoring during the first 24 hrs after resuscitation can contribute to the prediction of both good and poor neurological continuous electroencephalography monitoring for early prediction.
As with all monitoring techniques, the use of processed or raw EEG during cardiac surgery presents both advantages and disadvantages (Table 4). The effectiveness of BIS monitoring in preventing intraoperative awareness with postoperative explicit recall remains controversial.
Intraoperative monitoring is the use of electroencephalography and electromyography to help monitor and study the functional integrity of various neurological pathways, such as the nervous system, spinal cord and brain pathways, during surgery.
21 Theda, C. Use of amplitude integrated electroencephalography (aEEG) in patients with inborn errors of metabolism - a new tool for the metabolic geneticist. Mol Genet Metab. ; Suppl 1: S42 – 8. Conversely, the investigation becomes most cost effective when applied to specific problems--for instance, monitoring serial changes in postanoxic coma or during open heart surgery, differential diagnosis (by telemetric ictal recordings) of epileptic and non-epileptic attacks, and providing early prediction of outcome after stroke.